DESCRIPTION: This is an R29 proposal to study the interaction of c-abl and p53. The c-abl binding site on p53 will be determined by mutagenesis and correlated with biological activity. The effects of c-abl on p53 DNA binding and in vitro transcription activity will be tested. Finally the possibility that c-abl is a coactivator will be studied by testing for a transcriptional activation domain in c-abl using GAL4-c-abl constructs.